Fig. 6

UBE2O knockout upregulates PTRF expression in both cells and exosomes. A Western blots analysis compared the expression levels of PTRF in wild type and two clones of UBE2O KO HeLa cells. B Wild type and UBE2O KO HeLa cells were treated with 10 μM MG132 and DMSO for 4 h before the cell collection. Then, the expression level of PTRF in cells was analyzed by western blot. C Densitometry analyses of PTRF expression relative to GAPDH expression for the result of western bolt in Fig. 6B were shown by the graph. Data are the means \(\pm\) SEM, n = 4. ns means non-significant, *P \(<\) 0.05; **P \(<\) 0.01. D After wild type and two clones of UBE2O KO HeLa cells were cultured in serum-free culture medium for 40 h, the supernatants were used for exosomes isolation. Then, exosomes harvested from supernatants were identified by transmission electron microscopy. E Exosome samples from wild type and two clones of UBE2O KO HeLa cells were diluted in appropriate concentration to analyzed by NTA. F, G Exosomes from wild type and two clones of UBE2O KO HeLa cells were analyzed by western blot for the indicated antibodies